Fuel vaporizing system



March l, 1938. v Q B FAVERTY ET AL 2,109,743

FUEL. vAPoRIzING SYSTEM Filed July 30, 1932 Patented Mar. 1, 1938 UNITED STATES aioaus l FUEL vsroluzme SYSTEM Clyde B. Faverty, Henry J. Smith, and Peter C. L. Van Bueren, Chicago, Ill., assignors to Mark C.

Bates, chicago, n1.

Application July 30, 1932,` Serial N0. 627,162

6 Claims.

Our invention relates in general to vaporizing devices for liquid hydrocarbons. It relates more in particular to an improved method of controlling the operation of aspirators used in connection with such devices.

The invention has its greatest application to a vaporizing apparatus wherein the liquid hydrocarbon is vaporized in a vaporizing chamber and is withdrawn from the chamber by means of an aspirator .consisting of an air nozzle discharging into a Venturi tube, the connection from the vaporizing chamber being 'at the discharge end of the air nozzle. A vaporizer of this character is shown in the copending application of Charles A. French, Serial No. 603,491 filed April 6, 1932; of which the copending application of French,

Serial 684,656, filed August 11, 1933, is a division.

Such a vaporizer will operate over a considerable range depending upon the amount of heat desired, but cannot be controlled to produce a combustible mixture at rates appreciably below those for which the apparatus was designed.

The principal object of our invention is to make it possible in a vaporizer of this character to supply a combustible mixture in relatively large amounts or in relatively very small amounts without impairing the character of the mixture.

Another object is to modify the action of an aspirator in a device of this character whereby the amount of air may be decreased but the velocity thereof maintained substantially constant.

Another object is to make it `possible to cut down the amount of air without substantially decreasing the amount of vaporized hydrocarbon withdrawn from the vaporizing chamber.

Other objects and features of the invention will be apparent from a consideration of the following detailed description taken with the accompanying drawing, wherein Fig. 1 is a transverse sectional View, shown partly schematically, of a vaporizing device ern-- bodying the features of our invention;

Fig. 2 is a slightly enlarged fragmentary sectional view ofthe needle valve;

Fig. 3 is a fragmentary sectional view showing the modified arrangement of the control mechanism; and

Fig. 4 is a sectional view taken along the line 4--4 of Fig. 3, looking in the direction of the arrows.

In order that the details of the invention will be more manifest as `they apply to the operation of the vaporizer, we shall rst describe the vaporizer itself as it is disclosed in the drawing.

'Ihe vaporizing chamber I0 is adapted to contain a-predetermined level of liquid hydrocarbon I I, supplied to it through a. supply pipe I2. This pipe is connected to a float chamber I3 and the float chamber in turn is connected through a. pipe I4 to a fuel supply tank I6, the drawing also showing a strainer I1 in the line. A balance line I8 is provided connected above the iloat in the iloat chamber and to the vaporizing chamber I0, whereby the same vapor pressure is maintained in the float chamber as in the vaporizing chamber to which the fuel in liquid form is supplied.

A conduit I9 receives hot gases from a pilot burner 2|, the hot gases being controlled to descend in the conduit and pass up through thel contained liquid in the vaporizing chamber through a bubble plate 22, formed with a plurality of apertures through which the hot gases pass. An air line 23 supplied with air under pressure from a suitable source exhausts through a nozzle 24 into a Venturi tube 26 connected to a vapor delivery line 21 connected with the main burners (not shown). The vaporizer chamber is connected by a suitable passageway 28 controlled by butterfly valve 29 to the Venturi tube, an annular enlarged portion 3| being provided whereby the vaporized fuel from the vaporizing chamber is withdrawn from the passageway 28 by the suction induced by air owing through the Venturi throat at high velocity. The mixed air and vaporized hydrocarbon then passes through the line 21, whence it is burned in a suitable way and by means of suitable burners.

A short pipe formed in the shape of an elbow 32 extends into the vapor delivery passageway and connects to a burner nozzle v33, the discharge end of which is adjacent the opening of the conduit I9. A relatively small amount of a combustible mixture is withdrawn from the main delivery line and delivered to the burner nozzle 33 where it is burned, the hot gases passing through the conduit I9, as previously described, and causing a 'vaporization of the liquid hydrocarbon. An adjustable cap 34 is provided over the nozzle 33 which furnishes means for lighting the pilot light and also may be controlled to admit additional air, should the additional air be required for any purpose.

The volume of combustible mixture delivered to the main burners is determined by the amount of air delivered through the line 23 and also to some extent by the setting of the butterily valve 29. In general, however, the movement of air is the main control, as it is only by moving the.

air that the aspirator action is obtained and movement of hot gases promoted through the vaporizing chamber. i

We have discovered that by means of a nozzle control rod 36 extending through the center portion of the nozzle longitudinally thereof, we can so control the movement of air therethrough as to have a very much more eective control of the burner as a whole. In the form shown, .the rod has a tapered portion 36a and a threaded portion l1 extending through a threaded boss 3l forming a part of the frame and adapted to be turned by a hand wheel 39. By inserting the rod, we cut down the size of the opening in the air nozzle, that is the cross Sectional areaI thereof to discharge less air when less air is needed, but maintaining the velocity thereof around the outside of the air stream. This is the only portion of the air which has any immediateeifect upon the aspirating action, because it is the only portion in contact with the body of vapor fuel surrounding the stream of air. When the rod is adjusted to its most advanced position, there will be only a relatively small ring of air discharged and this air, much less in volume than in the setting of Fig. 2, will travel at the same or greater velocity than the air in Fig. 2 and cause at least as much aspirating action, that is, make it possible to Withdraw the same volume of vaporized fuel, should this be necessary. The amount of fuel withdrawn is then controlled by the setting of the butterfly valve 29.

It appears clear from the drawing that the rod can be still further withdrawn from the air delivery nozzle so as to have no effect whatsoever upon the delivery of air therethrough. Moreover, we may produce the rod without the taper and may, of course, employ other means for adjusting the same.

In the forms 'shown in Figs. 3 and 4, we also cut down the volume of air without cutting down the velocity thereof. In the form previously shown, the proportions of air and vaporized hydrocarbon were modified by control of the position of the rod. In the form We are now considering, however, the relative proportions remain substantially the same, the volume only being decreased.

A rod |36 is employed slidably supported in a gland or sleeve |38 and threaded into the central portion of a spider Ill. The rod carries a double cone |35, one conical portion extending by way into the nozzle |24 and also partially illlingout.

the annular portion 3| so that an annular restricted passageway |30 is formed in the Venturi opening. As will appear clear from the drawing, when the rod I 36 is adjusted on its threads it not only eiects the opening |25 between the cone and the nozzle |24, but also effects the cross sectional area of the opening |30. By controlling both of these openings together, the volume of combustible mixture delivered to the line |21 is substantially proportional to the volume of air delivered to the venturi through the opening |25.

The vaporizing apparatus per se, with which the control of Fig. 3 is employed, may be substantially the same as that shown in Fig. 1. Fig. 3 shows a portion of such apparatus and the same reference characters are employed as employed in Fig. 1, with the prex 1" for identification and to shorten the description.

It will be understood that although we employ two slanting surfaces together on a single cone, as the drawing shows, we may modify this con- `to thegases.

We have described our invention in detail to permit those skilled in the art to practice it, and have shown it with a specific type of vaporlzer with which it co-operates in a very eilicient manner. We do not restrict ourselves, however, to these features as shown and described, the invention being limited only by the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent of the United States is:-

l. In combination, a vaporizing chamber, means for maintaining a supply of liquid fuel in the chamber, a Venturi tube, a connection from the Venturi tube to said vaporizing chamber, an air discharge nozzle communicating with the Venturi tube, means for changing the effective cross sectional area of said air delivery nozzle, and means for delivering hot vgases below the surface of and through the fuel including means for withdrawing a combustible mixture as the gases leave the Venturi tube, means for burning said combustible mixture, and means for delivering the resulting products of combustion to the vaporizing chamber below the surface of the liquid fuel.

2. In an oil vaporizer, a vaporizing chamber, means for maintaining a body of oil in the chamber, as aspirator including an air delivery nozzle and a Venturi tube, a connection near the nozzle between the Venturi tube and the vaporizing cha'mber whereby oil vapors are adapted to be drawn into the tube and mixed withair from said4 air delivery nozzle, means for passing hot gases of combustion below the surface of and through-said oil to vaporize a portion of the same, and a tapered rod longitudinally movable in the air delivery nozzle to regulate the amount of air delivered to the Venturi tube and the amount of oil vapor drawn from said vaporizing chamber.

l3. In an oil vaporizer, a vaporizing chamber, means for maintaining a body of oil in the chamber, an aspirator including an air delivery noz zle and a Venturi tube, a connection near the nozzle between the Venturi tube and the vaporizing chamber whereby oil vapors are adapted to be drawn into the tube and mixed with air from said air delivery nozzle, a delivery line into which the mixture of air and oil vapor is delivered, means for withdrawing a portion of the mixed oil vapor and air from said delivery line, a burner for burning thewithdrawn mixed oil vapors and air, means for delivering the resulting hot gases of combustion to the vaporizing chamber below the level of liquid oil therein, and a tapered rod longitudinally movable in the air delivery nozzle to regulate the amount of air delivered to the Venturi tube and the amount of oil vapor drawn from said vaporizing chamber.

4. In an oil vaporizer, a vaporizing chamber, means for maintaining a body of oil in the chamber, means for maintaining a constant oil level in said ch ber, an aspirator including an air delivery n and a Venturi tube, a connection near the nozzle between the Venturi tube and the vaporizing chamber whereby oil vapors are adapted to be drawn into the tube and mixed with air from said air delivery nozzle, means for passing hot gases of combustion through said liquid to vaporize a portion of the same, and a tapered rod longitudinally movable in the air delivery nozzle to regulate the amount of air delivered to the Venturi tube and the amount of oil vapor drawn from. said vaporizing chamber.

5. In an oil vaporizer, a vaporizing chamber, means for maintaining a body of oil in vthe chamber, means for maintaining a constant oil le-vel in said chamber, an aspirator including an air delivery nozzle and a Venturi tube, a connection near the nozzle between the Venturi tube and the vaporizing chamber whereby oil vapors are adapted to be drawn into the tube and mixed with air from said air delivery nozzle, a delivery line into which the mixture of air and oil vapor is delivered, means for withdrawing a portion of the mixed oil vapor and air from said delivery line, a burner for burning the withdrawn mixed oil vapor and air, means for delivering the resulting hot gases of combustion to the vaporizing chamber below thelevel oi liquid oil and the amount of oil vapor drawn from said vaporizing chamber.

6. In combination in a fuel vaporizer, a vaporizing chamber containing a body of liquid oil, apilot burner, means for passing hot gases of combustion `below the surface of and through the oil in the vaporizlng chamber to vaporize a portion thereof, an aspirator for withdrawing vapors from said vaporizing chamber, said aspirator including a forcing nozzle and a Venturi tube, means for delivering air through said forcing nozzle whereby to Withdraw vapors from the vaporizing chamber and mix the same with air, a passageway for receiving the mixed air and vapor, means for trapping a portion of the mixed air and vapor and delivering the same to the pilot burner, and means for changing the cross sectional area of said forcing nozzle whereby the amount of combustible mixture delivered to said passageway and to the pilot burner is modified in proportion, and whereby the richness of said mixture remains substantially con-` stant independent of the amount thereof produced. i

CLYDE B. FAVERTY. HENRY J. SMITH,

PETER C. L. VAN BUEREN. 

